I am running exim4 with virtual users in a directory /etc/exim4/virtual and a router set up. I believe since I upgraded exim (while upgrading the whole system to Debian Lenny) the virtual router stopped working.
It doesn't even show up in the list of possible routers when debugging.
Anything of the type firstname.lastname@example.org gets delivered, but that's because it matches the local_user router.
The contents of my 350_exim4-config_vdom_aliases can be found here: http://pastebin.org/126176
In, I have replaced 01_exim4-config_listmacrosdefs local_domains = MAIN_LOCAL_DOMAINS with local_domains = MAIN_LOCAL_DOMAINS : dsearch;/etc/exim4/virtual